A gas hydrate is a kind of inclusion compound and refers to a stable crystalline material produced by physically enclathrating gas molecules having a low molecular weight, such as methane, carbon dioxide and nitrogen within a cavity formed from water molecules, under conditions of high-pressure and low-temperature in general. An incorporated gas molecule, “guest”, is entrapped within a solid lattice of the water molecule, i.e., “host”, having hydrogen bonds under low-temperature and high-pressure conditions. Currently, 100 or more gas molecules are known to form a gas hydrate.
Since the above described gas hydrate is generally formed at low-temperature and high-pressure conditions, formation of gas hydrate under the atmosphere at room temperature and normal pressure is difficult to occur. However, in the deep sea with low-temperature and high-pressure, or at oil and gas production facilities on land at which a high pressure is maintained, an environment capable of forming the gas hydrate is created naturally, and as a result, gas hydrates occur in unwanted places and cause trouble.
In particular, in the case of the oil and gas industry, pipelines producing oil and gas from the reservoir in deep sea and transporting the up to surface are likely to be exposed to high-pressure condition or situated in a low temperature and high pressure environment in the sea. The low molecular gases included within the produced fluid being transported or the low molecular gas that flows in pipelines are reacted with water or the like to form gas hydrates in a solid state. The gas hydrate formed in the pipelines as described above blocks the fluid in the pipelines and interferes with the transportation of the produced fluid. Also, once the hydrate is formed, it is very costly and time-consuming to remove the hydrate plug. Pipeline operation is required to be stopped for the removal of the gas hydrate. For this reason, many efforts have been made to inhibit the formation of gas hydrates in the oil and gas industry.
Inhibitors have been developed to prevent the formation of such gas hydrates. However, conventional hydrate inhibitors cannot sufficiently inhibit the formation of the gas hydrate, or a very significant amount of the inhibitor is needed to sufficiently inhibit the formation of the gas hydrate. Accordingly, there is a need to develop a new inhibitor capable of effectively inhibiting the formation of gas hydrates and a composition capable of further increasing the effect thereof.